font (n.1)

early 15c., "spring of water that collects in a pool," from Old French fontaine "natural spring" (12c.), from Medieval Latin fontana "fountain, a spring" (source of Spanish and Italian fontana), from post-classical noun use of fem. of Latin fontanus "of a spring," from fons (genitive fontis) "spring (of water)," according to Watkins from PIE root *dhen- (1) "to run, flow" (source also of Sanskrit dhanayati, Old Persian danuvatiy "flows, runs").

The extended sense of "artificial jet of water" (and the structures that make them) is recorded by c. 1500. Hence also fountain-pen (by 1823), so called for the reservoir that supplies a continuous flow of ink. "A French fountain-pen is described in 1658 and Miss Burney used one in 1789" [Weekley].

Fountain of youth, and the story of Ponce de Leon's quest for it, seem to have been introduced in American English by Hawthorne's "Dr. Heidegger's Experiment" (January 1837).

"Did you never hear of the 'Fountain of Youth'?" asked Dr. Heidegger, "which Ponce de Leon, the Spanish adventurer, went in search of two or three centuries ago?"

also type-face, 1852, "top of a type," from type (n.) in the printing sense + face (n.). In modern common use, synonymous with font (n.2), but there is a technical distinction: the typeface is the set of characters of the same design; the font is the physical (or electronic) means of producing them.

Proto-Indo-European root meaning "to pour, pour a libation."

It forms all or part of: alchemy; chyle; chyme; confound; confuse; diffuse; diffusion; effuse; effusion; effusive; fondant; fondue; font (n.2) "complete set of characters of a particular face and size of type;" found (v.2) "to cast metal;" foundry; funnel; fuse (v.) "to melt, make liquid by heat;" fusible; fusion; futile; futility; geyser; gush; gust (n.) "sudden squall of wind;" gut; infuse; ingot; parenchyma; perfuse; perfusion; profuse; refund; refuse (v.) "reject, disregard, avoid;" refuse (n.) "waste material, trash;" suffuse; suffusion; transfuse; transfusion.

It is the hypothetical source of/evidence for its existence is provided by: Greek khein "to pour," khoane "funnel," khymos "juice;" Latin fundere (past participle fusus) "melt, cast, pour out;" Gothic giutan, Old English geotan "to pour;" Old English guttas (plural) "bowels, entrails;" Old Norse geysa "to gush;" German Gosse "gutter, drain."